Gas generant compositions for inflating automotive airbags are most commonly based on sodium azide, which, on inflation, produces nitrogen gas. However, due to toxicity and stability problems, there is a significant movement away from sodium azide as a fuel, and a number of non-azide gas generant formulations have been proposed, e.g., U.S. Pat. Nos. 4,369,079, 4,370,181, 5,197,758, and 5,431,103, the teachings of each of which are incorporated herein by reference. Non-azide formulations, however, tend to present their own problems, such as generation of particulates and generation of noxious gases. Thus, there remains a need for safe, effective gas generants for inflating automotive airbags and the like.
It has been thought to use ammonia ligands of cupric nitrate, i.e., Cu(NH.sub.3).sub.4 (NO.sub.3 ).sub.2 and Cu(NH.sub.3).sub.2 (NO.sub.3).sub.2 as fuels in gas generants. However, the first (four ammonia ligands) has proven to be unstable. The second (two ammonia ligands) is a stable compound, but proves to be hydrolytically unstable, i.e., adsorbs atmospheric water, a characteristic highly undesirable in a gas generant composition.